Bacterial Adhesion and Interaction with Biomaterial Surfaces - Biointerfaces: Where Material Meets Biology - page 382

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Figure 13.9 Representative scanning electron microscopy images of S. epidermidis
RP62A on (a) smooth and (b) textured 400/400 nm polyurethane sur-
faces after 2 days incubation.
Reproduced from Xu and Siedlecki 153 with permission from Elsevier.

biofilm of S. aureus on a smooth surface, and individual bacteria/cluster on a
500/500 nm patterned surface.
A similar experiment was also carried out on another textured pattern
surface with dimensions of 400/400 nm and the fraction of accessible sur-
face area of 27.5%. Significant reduction in adhesion was obtained on the
textured surface. 153 With an incubation of 2 days, biofilm and large clusters
of bacteria aggregates were formed on a smooth surface and only individual
bacteria were attached on a textured 400/400 nm surface (Figure 13.9).
Therefore, it can be concluded that surface texture and the concomitant
reduction in accessible surface area leads to inhibition of bacterial adhesion
and subsequent biofilm development. Results suggest that surface texture
may provide a novel approach to resist staphylococcal bacterial adhesion
and biofilm formation on a material's surface and prevent the biomaterial-
associated infections.

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13.5 Bacterial Adhesion Assay Methods and
Techniques Used in Studying Bacteria-Material
Interactions
Various different methods and techniques have been used to evaluate
bacteria-material interactions in either quantitative or qualitative manners,
and can be described as two major categories. One is the macro-scale an-
alysis of bacterial adhesion that utilizes fluid flowing against the adhered
cells and counts the number or percentage of cells attached, aided with
microscopy techniques and various labeling methods including radio-
activity, fluorescence, and crystal violet staining. 154 The other one is the
micro- or molecular scale analysis of interaction forces of single cell with